Luminaires are generally constructed to distribute light in accordance with the lighting requirements of a particular application. Luminaires are designed to distribute light in both a vertical plane and a horizontal plane. Sometimes it is desirable to have an adjustable luminaire, so that the reflected light pattern in either the vertical plane or the horizontal plane can be adjusted.
Generally, luminaires are designed to take into account a number of consideration and trade-offs, including functionality, aesthetics, cost, mounting location and mounting method, ease of affixation, ease of adjustment, size, weight, etc. In particular, the mounting location and method of installation has an effect on all of the above.
There are a number of ways that adjustable luminaires are mounted and adjusted. The first is a swivel arrangement, whereby the luminaire is attached to a surface or other mounting device using a single swivel mount. This swivel mount is exterior to the luminaire housing and can detract from the visual appeal of the luminaire. Generally, the entire luminaire housing must be moved in order to adjust the light pattern.
A second type of mount uses a yoke assembly, which generally attaches on both sides of the luminaire housing. This suffers from the same visual deficiencies as the swivel mount, and the entire housing generally must be moved to adjust the light pattern.
A third type of luminaire of this type is adjustable internally, whereby the reflector, and possibly other components, are moved internal to the luminaire housing. While visually appealing, this type of luminaire may lack the adjustability of the above devices.